The present invention relates generally to an apparatus for forming components from a continuous stock of wire, strip or tube.
Modern wire forming and spring making machines combine a wire feeding mechanism, multiple cam actuated forming tools to bend the wire in required different directions and a cutoff tool to sever the finished part from the wire stock. However, when a change is required or a new part is to be manufactured, it is a costly and time-consuming process to either adjust the operation of the tools or replace the tools for the current part with a new set of tools for the new part.
Historically, wire forming and spring making companies have pursued speed as the answer for much needed productivity improvements. But in many cases, speed alone may compound existing quality and inventory related issues. Complicated parts requiring secondary or multiple operations will accumulate at high speed during the primary operation, only to wait in staging areas to be completed with slower operations such as coining, trimming, looping, broaching, bending, chamfering, etc.
Naturally, optimum speed will always be a basic issue, but for many production parts this should not be the main focus. Since no component can be completed faster than its slowest operation, starting there and working backwards makes sense when establishing the best production process. Next, utilizing automation to tie these operations together reduces labor, inventory and the cost of quality. Redundant inspections will be eliminated.
The present invention concerns a modular forming apparatus for forming components from continuous stock supplied by a stock feeder. A tool bed mounted on a base has a plurality of horizontally extending tooling rails mounted on a vertical front surface for selectively and releasably attaching one or more of a plurality of tool pallets. A source of pressured fluid (hydraulic and/or pneumatic) is connected to actuators for the tools for performing forming operations on stock received from the stock feeder. The tool actuators mounted on the pallet are connected to the fluid source through valves operated by a control panel. The tool pallets are easily replaced for maintenance or changeover to a new component. The control panel generates a plurality of screens for programming, testing and automatically running programs consisting of forming steps to be performed.
In response to a growing demand for equipment which can automatically produce completed wire, strip or tube components, the present invention is a unique production machine that enables the user to eliminate costly secondary operations by capturing and transferring components during the production process.
Unlike conventional cam driven mechanical systems such as fourslides or other geared forming machines, the modular machine according to the present invention is not limited by cam rotation, tool bed space or slide position. A vertical machine bed allows automated in-line production that can include operations originally performed as secondaries.
Whereas mechanical cam actuated forming machines have fixed tool paths that place limits on tool positioning, the modular machine according to the present invention utilizes hydraulic or pneumatic cylinders for tool actuation, allowing almost infinite tool positioning options. The use of keyed tooling rails on a bed allows the mounting of slides and form-tools above, below, behind or in front of the wire line, at any required angle. Multi-plane forming is never a problem.
Another advantage of the hydraulic forming system according to the present invention is the ability to increase or decrease the forming power for each individual slide simply by selecting the required, hydraulic cylinder tonnage. Whereas typical slide machines have identical tonnage on every slide, the modular machine enables the technician to have additional power when needed.
Since cams are limited to their dwell (normally fast in/out tool movement) and 360xc2x0 rotation, slide time on the tool is severely limited. In the case of many spring steel parts, the hydraulically actuated cylinder slide of the present invention can actually dwell (using time delays) on a specific point, creating a xe2x80x9csettingxe2x80x9d action for the tool. This is particularly useful for critical dimensions or compensating for material spring-back.
Also, the speed of entry or retraction can be set for each slide of the present invention simply by adjusting the individual flow controls for each valve. This feature is particularly important when the technician wishes to prevent a long material segment from whipping during the forming process. By slowing the cylinder action, the material will move smoothly into position, assuring the success of the following operation.
Designers no longer need to worry about completing a specific part within the normally required 360xc2x0 of cam rotation. This constant limitation is eliminated through the use of cylinder actuated slides and tooling in the modular machine according to the present invention. Timing becomes less a factor of tool design and more of a total process issue.
Through the use of a touch screen interface or MMI (Man-Machine-Interface) for programming, designers can xe2x80x9cfirexe2x80x9d tools independently, in any sequence or in any combination, during any step of the setup process. Any machine input may be actuated on demand, simplifying and shortening the setup and tryout process. Repeated xe2x80x9chitsxe2x80x9d can be made with individual tools without cycling the machine through any other phase of the program. Once a step or operation is satisfactorily completed, the tool designer or technician can move on to the next operation. After all of the individual operations are completed, they can be tried in partial or total sequence until the final part is correct.
Ultimately, after the tooling is proven station by station, the transfers are installed to move the component from operation to operation, across the face of the machine. Successful transfer to, and completion of each additional operation, is achieved by never losing control of the part.
The modular machine according to the present invention also includes the ability to run two parts at the same time. By placing feed systems on both sides of the machine, the machine can produce two identical or different parts as needed. This feature is often used to increase capacity without adding another machine. The dual feed system also provides the opportunity to assemble the two components by transferring one to the other.